Current Institute of Electrical and Electronics Engineers (IEEE) 802.11b/g wireless local area network (WLAN) standards offer the convenience of wireless connections with adequate performance for many tasks. The IEEE 802.11b standard corresponds to IEEE Std. 802.11b-1999 entitled “Local and Metropolitan Area Networks, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications: Higher-Speed Physical Layer Extension in the 2.4 GHz Band,” approved Sep. 16, 1999 as well as related documents. The IEEE 802.11g standard corresponds to IEEE Std. 802.11g-2003 entitled “Local and Metropolitan Area Networks, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, Amendment 4: Further Higher Rate Extension in the 2.4 GHz Band,” approved Jun. 27, 2003, as well as related documents. Related documents may include, for example, the IEEE 802.11a standard.
However, for some operations under current WLAN standards, such as streaming high quality multimedia content, throughput provided by these standards may not be adequate. In response to demand, IEEE approved the creation of the IEEE 802.11 Task Group N (TGn) to define modifications to the Physical Layer and Medium Access Control Layer (PHY/MAC) to deliver 100 megabit-per-second (Mbps) or greater throughput. The result is an upcoming specification referred to as ‘IEEE 802.11n’ that is an addition to the 802.11 family of standards that is intended to increase wireless network speed and reliability.
IEEE 802.11n communications are based on multiple input, multiple output (MIMO) technology that uses multiple antennae at both the transmitter and receiver sides of a communication link. The 802.11n standard may use orthogonal frequency-division multiplexing (OFDM) to increase speed, as well as techniques to transmit multiple redundant copies of data to increase reliability. With prior art standards, a 20 MHz channel bandwidth was utilized. However, MIMO approaches using only 20-MHz channel require higher implementation costs to meet the IEEE TGn requirement of 100 Mbps throughput. Meeting the IEEE TGn requirement with only 20-MHz channels would require at least three antenna analog front ends at both the transmitted and receiver. At the same time, a 20-MHz approach will struggle to provide a robust experience with applications that demand higher throughput in real user environments.